Artificial Gravity: That's Heavy, Man

Jonathan Strickland

Courtesy NASA

Yesterday, NASA held a pretty cool Google+ Hangout event with astronauts, NASA experts and some of the cast and crew of Star Trek Into Darkness. If you missed it yesterday, don't worry. The entire presentation has been recorded for posterity.

One thing that was touched upon in the Hangout was that in science fiction films, you almost always see spacefarers walking around on space stations or ships. Some sort of artificial gravity keeps feet on the ground and coffee mugs on the table (not to mention coffee in the coffee mugs). One member of the Internet audience posed the topic as a question: Are we actually working on artificial gravity?

The initial response from astronaut Michael Fincke was that floating around in space is way more fun than obeying gravity. I'm sure that's true, but artificial gravity would be incredibly useful. For one thing, a big problem with a prolonged visit to space is that your bones begin to deteriorate in a zero-g environment. Simulated gravity could give us the opportunity to go on longer space journeys without risking bone density loss.

Artificial gravity could also help us design new propulsion or even energy systems. But it would also mean designing ships so that they work in a particular orientation. Right now, if you can float so that you can interact with environments in multiple ways, your design options are really flexible. But if we must adhere to gravity, ship or station design will have to reflect that.

This HowStuffWorks article goes into detail about how science fiction often gets things wrong or at least ignores troublesome details in order to tell a compelling story. Part of that is the problem of artificial gravity. One way we could simulate gravity is through rotation. If you rotate a spacecraft around a central axis, you generate centripetal force toward that axis. Everything inside that spacecraft will feel a pull to the outer edge of the craft -- it's what we refer to colloquially as centrifugal force.

So imagine a space station in the shape of a bicycle wheel. As the wheel rotates in space, everything inside the station is pressed outward toward the edge of the station. This sort of artificial gravity would be adjustable based upon the speed of rotation. But it might not be ideal and it would require designing all stations and craft so that the floor is all along this outer edge.

The world of Star Trek doesn't have this problem -- there's some other form of artificial gravity that keeps everything in place. Not only that, but there are also these things called inertial dampeners that keep people from flying out the back of the Enterprise when the ship goes into warp. Normally, momentum would play a role and people would quickly transform from Starfleet officers into an icky goo as they were slammed around a ship under inconceivable acceleration forces.

So how do inertial dampeners work? Beats me. It's completely in the fiction part of science fiction. But such a technology would be necessary if we wanted to survive any type of travel that involves rapid acceleration or deceleration.

It could be that we learn the secrets of gravity over the next few decades. Perhaps we'll learn the actual mechanism that makes gravity work. It's something quantum physicists and other scientists have been working on for more than a century. If we do crack that quantum nut and learn how to harness gravity ourselves, the future we live in might make Star Trek seem quaint and archaic in comparison.